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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
    <script>
        let num=10
        if(num>20){
            console.log('数字大于20')
        }else{
            console.log('小于20')
        }
        let nums=3
        if (nums<10){
            console.log('数字小于10')
        }
        else if (nums>10 && nums<20){
            console.log('大于10小于20')
        }
        else{
            console.log(1)
        }
    </script>
</body>
</html>
